Abstract: A tool for stabilizing and supporting a vehicle by forming a rigid member between a bearing surface and the vehicle comprising at least one member having a cylinder and a movable piston that protrudes axially from the cylinder at a cylinder end. The cylinder end is formed with a pair of inclined circumferential surfaces. A collar extends axially from the cylinder and slidably receives the protruding piston. The collar is formed with a pair of internal annular step surfaces corresponding to the cylinder end surfaces. The collar step surfaces and the cylinder circumferential surfaces are engagable to permit rotation and simultaneous axial movement of the collar with respect to the cylinder. A pin is selectively positionable at one of a plurality of holes along the piston for engagement with the collar to prevent movement of the piston with respect to the collar. A locking system is provided for releasably securing the collar against rotation relative to the cylinder.